Twa Crash Probe Leaves Puzzles, Stricter Standards

March 04, 2001|By Andy Pasztor, The Wall Street Journal.

An extensive investigation into the crash of Trans World Airlines Flight 800 may have failed to pinpoint the cause, but the probe is triggering new safety measures and a reassessment of airplane design that will benefit passengers.

TWA Flight 800, en route to Paris, crashed shortly after takeoff from New York's Kennedy Airport on July 17, 1996, killing all 230 people aboard. Despite four years of sleuthing, investigators weren't able to determine what triggered the violent fuel-tank explosion that broke off the front end of the Boeing 747.

The National Transportation Safety Board, which led the probe, recovered tens of thousands of fragments of the wreckage, enlisted experts from around the world, dissected mothballed planes and even disproved sabotage theories by test-firing Stinger missiles. All told, the NTSB and Boeing Co. spent $67 million, a record for any jet crash.

In the process, however, the safety board's insights became catalysts for measures that should better protect fliers. When investigators open a public hearing Tuesday in Washington, D.C., to release their findings, they will spell out how Industry and government have embraced stricter standards to upgrade today's jet fleet and are enhancing the safety of planes on the drawing board. The new requirements, which range from making fuel mixtures less flammable to devising wiring that prevents dangerous power surges, will affect more than the particular airplane type and parts implicated in the TWA 800 tragedy.

"We have, in fact, looked at things differently" since Flight 800, says Thomas McSweeny, head of aircraft certification at the Federal Aviation Administration. Regardless of whether a safety threat is "considered to be very, very remote," such as a repeat of the blast that destroyed the 25-year-old TWA jet, he says the agency is determined to "go well beyond practices of just a year or two ago" to require fixes. "We're looking at yesterday's airplanes with today's technology in mind."

Industry critics continue to fault the FAA and Boeing for waiting too long to take action. Flight 800 "should have immediately galvanized everyone," says Paul Hudson, executive director of the Aviation Consumer Action Project in Washington, D.C. As a member of an FAA advisory group, Hudson in July 1998 issued a strong dissent to the majority's conclusion at that time to postpone action. "They recommended doing essentially nothing and studying problem," he says.

Still, previous accidents haven't provoked the regulatory response that resulted from the crash of TWA Flight 800. Prompted by initial theories that the 747 was downed by terrorists, Congress, the White House and the media closely followed the investigation.

Investigators, increasingly frustrated by their inability to find the source of the single spark or short circuit that touched off the deadly chain of events, began delving into every cranny of the 747's fuel system. From there, it was a logical step for regulators to start examining other systems on other models.

The most intensely scrutinized crash in history drove something fundamental home to investigators--that the practice of putting into service a steady stream of "derivative" aircraft, slightly different versions of time-tested models such as the Boeing 747, could perpetuate serious problems.

Critical systems on each successive version of such planes, made not only by Boeing but also by Europe's Airbus Industrie, were basically grandfathered in under old rules, some dating 20 years or more when the initial models in some aircraft families received government approval.

Historically, the industry saved considerable time and money as a result of this practice, because it didn't face comprehensive new requirements every time to prove that systems such as fuel tanks, flight controls and electrical wiring complied with state-of-the-art engineering safeguards. The FAA, for instance, allowed insulation to be installed on thousands of planes that wasn't up to flammability standards. It also permitted certain cargo bays to be built without any of the fire-protection equipment currently required.

The rudder mechanism on the original Boeing 737, for example, is the prime culprit in a string of dangerous and sometimes fatal in-flight upsets. The design probably wouldn't pass muster under current engineering standards, yet it has continued to get the green light in each consecutive generation of the widely used plane, according to John Purvis, Boeing's former chief accident investigator.

Armed with lessons gleaned from TWA 800, the FAA is requiring manufacturers to fundamentally alter the way they design, maintain and use fuel tanks in all newly designed aircraft. The goal is to reduce flammability and the possibility that damaged wire or a power spike could result in an explosion.